create [unique|fulltext|spatial] index index_name
 [using index_type]
on tbl_name(index_col_name, ...);

index_col_name:
 col_name [(length)] [asc/desc]

ALTER [IGNORE] TABLE tbl_name
 alter_specification [, alter_specification] ...

alter_specification:
 ...
 ADD INDEX [index_name] [index_type] (index_col_name,...)
 ...

mysql> create index cityName on city(Name(10));
mysql> alter table city add index cityName(Name(10));

drop index index_name on tbl_name;

create [or replace][algorithm = {undefined|merge|temptable}]
 view view_name[(column_list)]
 as select_statement
 [with [cascade|local] check option]

alter [algorithm = {undefined|merge|temptable}]
 view view_name[(column_list)]
 as select_statement
 [with [cascade|local] check option]

-- 包含聚合函数
mysql > create or replace view payment_sum as 
 -> select staff_id,sum(amount) 
 -> from payment
 -> group by staff_id;

-- 常量视图
mysql > create or replace view pi as 
 -> select 3.1415926 as pi;

-- select中包含子查询
mysql > create view city_view as
 -> select ( select city from city where city_id = 1);

drop view [if exists] view_name [,view_name] ... [restrict|cascaded]

mysql> drop view pay_view1,pay_view2;
Query OK, 0 rows affected (0.00 sec)

show table status [from db_name] [like 'pattern']

mysql> show table status like 'pay_view' \G
*************************** 1. row ***************************
  Name: pay_view
  Engine: NULL
 Version: NULL
 Row_format: NULL
  Rows: NULL
 Avg_row_length: NULL
 Data_length: NULL
Max_data_length: NULL
 Index_length: NULL
 Data_free: NULL
 Auto_increment: NULL
 Create_time: NULL
 Update_time: NULL
 Check_time: NULL
 Collation: NULL
 Checksum: NULL
 Create_options: NULL
 Comment: VIEW
1 row in set (0.00 sec)

mysql> show create view pay_view \G
*************************** 1. row ***************************
  View: pay_view
  Create View: CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `pay_view` AS select `pay`.`pid` AS `pid`,`pay`.`amount` AS `amount` from `pay` where (`pay`.`amount` < 10) WITH CASCADED CHECK OPTION
character_set_client: gbk
collation_connection: gbk_chinese_ci
1 row in set (0.00 sec)

mysql> select * from information_schema.views where table_name = 'pay_view' \G
*************************** 1. row ***************************
 TABLE_CATALOG: def
 TABLE_SCHEMA: mysqldemo
  TABLE_NAME: pay_view
 VIEW_DEFINITION: select `mysqldemo`.`pay`.`pid` AS `pid`,`mysqldemo`.`pay`.`amount` AS `amount` from `mysqldemo`.`pay` where (`mysqldemo`.`pay`.`amount` < 10)
 CHECK_OPTION: CASCADED
 IS_UPDATABLE: YES
  DEFINER: root@localhost
 SECURITY_TYPE: DEFINER
CHARACTER_SET_CLIENT: gbk
COLLATION_CONNECTION: gbk_chinese_ci
1 row in set (0.03 sec)